In wireless communications networks, there are some mobile devices equipped with Global Positioning Systems (GPS) or other location determination mechanisms that can provide the location information to the communications network. However, there are a large number of mobile devices that do not have location determination mechanisms and/or do not have the means to autonomously provide accurate location information to the communications network.
The mobile service provider's knowledge of the precise location of mobile devices at all times within the communications network can provide valuable benefits to users of the mobile devices as well as opportunities for improved or additional services above and beyond basic connectivity services. Typical communication networks provide access to various communication services (e.g., voice, video, data, messaging, content broadcast, Voice over Internet Protocol (VoIP), and so on) for mobile devices. Further, knowledge of the precise location of the mobile devices within the communication network at all times can allow for location-centric services or information associated with the mobile device to be provided. For example, services such as Emergency 911 (E911) services, mapping services, traffic information services, advertising services, and other services can be provided as a function of the location. Further, mobile device location information can be employed to improve network performance, to troubleshoot networks, to assist local law enforcement, to aggregate valuable demographic information, and an unlimited number of other uses.
Since a large number of mobile devices might not have mechanisms for determining location and/or continuously reporting such information, various solutions have been proposed for determining location information uniformly for all devices at the same time. For example, some techniques include measuring the timing delay of the signals transmitted between a wireless base station and the wireless handset and applying various location services or methods, including, but not limited to, cell global identity and timing advance (CGI+TA), CGI and round trip time (CGI+RTT), time of arrival (TOA), or other custom methods. Such networking timing delays include site timing delay in the wireless signal path among radio component(s) at the wireless base station and a sector antenna. Network timing delays can also include delays that can arise from various mismatches (e.g., impedance mismatch) among electronic elements and components, stray capacitances and inductances, length of the antenna(s) cable(s) in base station(s); tower height of the base station, signal path scattering, or “signal bounces,” such as multipath or strong reflections, and the like. Propagation delay between a mobile device and a NodeB is conventionally assumed to be negligible with respect to timing delay. However, depending on the architecture of the serving base station and covered sector antenna(s) signal propagation delay can be substantive, particularly in distributed antenna systems and low-power wireless radio cells and can cause significant error in mobile device location determinations as proposed by traditional techniques.
Other conventional techniques use a small number of GPS-reporting mobile stations to develop fingerprints and/or to solve multiple simultaneous equations as needed to calculate the location of devices that report measurements. For example, some conventional techniques involve solving multiple simultaneous equations at the time of arrival of new timing measurements from mobile devices of unknown location. The time required to solve the equations is lengthy, fundamentally driving up the cost of the many equations that must be solved at a rate equal to the arrival of messages from mobile devices having unknown location.
Some other techniques have attempted to solve the location problem by using a bin-fingerprinting technique. In this technique, the number of bins that must be searched to find a bin that best matches the reported measurements can be time-consuming since the number of bins can be large. This is especially true if the bins must be cubes as might be used to support the calculation of altitude values. Consequently, it would be desirable to have the ability to quickly determine location information of one or more devices in an efficient manner.
Conventionally, various solutions have been proposed for determining location information. However, none of the solutions proposed for determining location information has addressed all of the above requirements and such a solution would be desirable to significantly improve efficiency of determining location information.
The above-described deficiencies of today's location systems and techniques are merely intended to provide an overview of some of the problems of conventional systems, and are not intended to be exhaustive. Other problems with conventional systems and corresponding benefits of the various non-limiting embodiments described herein may become further apparent upon review of the following description.